T0 is the first set of castings produced from a newly built die. Its purpose is not to produce good parts, it is to find out what the tool actually does before anyone commits to production.
Tool makers, OEM R&D teams and design houses all reach the same point: the die is finished, the drawing looks right, and the only way to know whether it works is to put metal through it. That is the T0 trial.
What T0 actually proves
- Does the cavity fill completely? Misruns and cold shuts show up immediately, usually at thin sections or the last areas to fill.
- Does the part eject cleanly? Sticking, drag marks and distortion on ejection are tooling problems, not process problems.
- Where does flash form? Flash indicates parting line fit and clamping behaviour under injection pressure.
- Is venting adequate? Trapped air appears as porosity clusters in predictable locations.
- Does the part measure to drawing? Shrinkage rarely matches the theoretical allowance exactly on the first attempt.
What you should receive from a T0
A trial is only useful if it generates information. From a T0 run you should expect:
- Sample castings, clearly identified, in enough quantity to measure and test
- The process parameters used, injection speed, pressures, die and metal temperatures
- Observations on fill behaviour, ejection, flash and any visible defects
- A view on what the tool needs before it can run production
Parts alone are not a trial result. If a supplier hands back castings without telling you what happened during the shot, you have lost most of the value.
What usually needs correcting after T0
It is rare for a tool to be production-ready at T0, and that is not a reflection on the tool maker. The common corrections are:
- Venting, added or enlarged where gas is trapping
- Gating, reshaped to change how the flow front travels
- Cooling, adjusted where the part is distorting or sticking
- Shrinkage compensation, dimensions corrected where the part came out undersized
- Draft and polish, improved where ejection is dragging
A trial is only representative if it runs on the equipment that will make the parts. We run trials on our 500T, 1000T and 1250T machines, the same machines used for series production, so a successful T0 needs no re-validation on different equipment later.
How many parts do you need?
Fewer than most people assume. For dimensional verification and basic fitment, 25 parts is usually enough to see both the average and the spread. If you need destructive testing, pressure testing or customer sample submission, you may want more.
We run trials from 25 components upward, with no requirement to commit to series production afterwards.
Who owns the tool?
Your tooling remains your property throughout. NDAs are respected on all development work, and drawings and 3D data are used solely to run your trial.
Full details of how we run trials are on our T0 trials page.
Have a part you need quoted?
Send us the drawing and expected volume. We reply within 24 hours with a quotation or the questions we need answered first.
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